Silencer



Aug. 16,1927. 1,639,047

H. P. MAXIM SILENCER Filed Aug- 7. 1924 2 Sheets-Sheet l b w l is r l l V /\y r L J l L J INVENTOR 'www #22d ATTORNEYS Aug. 16,1927. l 1,639,047

H. P. MAXIM SILENCER Filed Aug- '7, 1924 2 Sheets-Sheet 2 v 'INVENTOR BY www* 7h23 ATTORNEYS Patented Aug. 16, 1927.

UNITED STATES HIRAM PERCY MAXIM, OF HARTFORD, CONNECTICUT,'ASSIGNOR TO THE MAXIM SILENCER COMPANY, OF HARTFORD,

NECTICUT.

CONNECTICUT, A CORPORATION OF CON- SILENCER.

Original application -filed January 25, 1923, Serial No. 615,434. Divided and this application med .August 7, 1924. Serial No. 730,758.

exhaust noises of internal combustion engines. Although not limited thereto, cerl tain features of the invention are particularly adapted for embodiment in silencers of relatively large size for use in connection with powerful oil engines and the like.

The invention is particularly directed to Il improvements in the class of silencers described in my pending application Serial No. 615,434, filed January 25, 1923, of which this present application is a division.

One object of the invent-ion is to provide 1U improved means for first permitting the ysound waves to expand greatly, and as a result their noise value per unit of volume is greatly reduced with provisions for taking the exhaust gases or other sound wave n propagating medium at the zone of greatest sound wave expansion and conducting same through a subsequent circuitous course.

Another object of the invention is to provide a silencing unit of improved and simu plified construction capable of cooperating with similar units 'to aiford increased silencing capacity whereby, in a silencer of given dimensions, more or less silencing capacity may be provided by the assembling together of a larger or smaller number of said units.

Further objects of the invention are to provide certain improvements tending to insure strength and rigidity of construction (more particularly in silencers of large sizes such as are required to silence the exhaust lnoises of large and powerful engines): to facilitate the economical quantity production of silencers of large capacity; to render practical the construction of large silencers in which provision is made for v arying the capacity thereof; and to provide various other improved features of construction contributing to the production of efficient and reliable silencers at low manufacturing cost-s. To the accomplishment of the above and further objects as will hereinafter appear, the invention consists in the features of construction and in the `combinations and ar-A rangements of parts which will first be de.

Fig. 1 is a longitudinal sectional view of a silencer constructed in accordance with the prese-nt invention; and F Figa 2 is a transverse sectional view pf Referring to the drawings the improved ,silencer therein shown comprises a cylindrical casing or shell 55, and end plates 56 and,

57, the latter being provided with central inlet and outlet apertures 58, and 59 respectively. A silencing element 60, correspending to the series of silencer units of the form described inl my pending application Serial No. 615,434, filed January 25, 1923, is located adjacent the outlet end of the device, said element being constructed and arranged to provide a series of spiral silencing passages through which the exhaust gases are constrained to pass after leaving an expansion chamber 61 at the inlet end of the device.

The silencing element comprises a se-r ries of shells 62 each of which is circular so arranged that when viewed in cross-sec-A tion as in Fig. 2, the inner end of each shell abuts and slightly overlaps the outer end of the shell of the next smaller size. In the drawing four such shells are provided, the innermost shell being modified slightly in construction, in that it .is curved in crosssection to form one and one-half turns instead of a single turn only, as in the case of the other shells. At the opposite trans; verse edge of each shell 62 is formed a flange 64 which projects inwardly at right angles tothe shell and each shell 62 is further provided with a series of parallel transverse ribs 65 which are equally spaced apart between the flanges 64, as shown, to provide a series of spiral channels 66, the series of channels of each successive shell continuing the series of channels formed by the ypreceding shell. The outermost ribs 64 of each shell are shaped so that their free edges will engage the unribbed face of the next smaller shell, said ribs thus serving to space apart the several shells and support them in assembled relation. 'The innermost shell 63 .is provided with a similar series of spacedapart transverse ribs which are alined with the ribs 65 and which continue the channels 66 to a central chamber 67 which extends from one end of the silencing element 60 to the other. The innermost shell 63 is closed at the end nearer the inlet 58 by means of an end wall 68. The transverse ribs of the innermost shell 63 terminate before reaching the inner longitudinal edge of the shell so as to leave the central chamber 67 entirely,

unobstructed to permit an uninterrupted flow of the gases outwardly therethrough.

An in-turned flange 73 is provided on the shell 63 at the outlet end of the silencing element, this -lange corresponding to the .anges 64, and the flanges 64 and 73 are rigidly secured to the end plate 57 by means of bolts 69 which extend through said plate and are threaded into said flanges. Thus the several shells 62 and 63 are firmly held in assembled relation. The outer shell 62 is vsupported at its outer end by means of a plurality of lugs 70 on the4 inside of the casing shell 55. The ribs 65 of each shell 62 extending substantially to outer surface of the next smaller shell, the channels 66 between the ribs are substantially closed along all four sides and thus provide a series of substantially independent spiral silencing passageways 71 which are arranged side by side throughout the length of the silencingy element 60.

It will be seen that the outer shell 62 is surrounded by a narrow annular chamber 7 2 which is in communication, between the lugs 70, with the expansion chamber 61. In use, the gases and sound waves pass through the expansion chamber 61, the annular chamber 72 and the spiral silencing passageways 71 in the same manner and with the same eifect as through similar portions of the silencer describedD in my pending application Serial No. 615,434 iled J an. 25, 1923.

A silencer designed as illustrated in the drawings can be constructed economically, all parts being cast and the several shells being readily assembled and firmly secured in place b means of the bolt 69. The shells of the si encing element 60 being rigidly supported at onl one end are free to contract and expan under changing temperature conditions, both independently of each other and of the outer easing.

The invention having been described, what is claimed is 1. In a silencer, a winding passageway for the sound waves formed by a plurality of channel-like sections, each section curved longitudinally of the channel to form one convolution of an approximate spiral and the sides of said channel arranged to form the sides of said passageway, the several sections being progressively smaller in size and arranged with the inner extremity of a larger spiral section abutting and overlapping the outer extremity of a next smaller spiral section, and means for rigidly securing said sections in assembled relation.

2. In a silencer, awinding passageway for the sound waves formed by a plurality of substantially spiral sections.` each having a plurality of parallel ribs extending longitudinally along its inner face, each of the several sections being curved to form a single convolution of a spiral and being progressively smaller in size and arranged with the .inner extremity of alarger spiral section abutting and overlapping the outer extremity of a next smaller spiral section, the ribs of each smaller section having their free edges substantially in contact with the unribbed faces of a next larger section to form spiral silencing passageways, and means for rigidly securing said sections in assembled relation.

3. In a silencer, a winding passageway for the sound waves formed by a plurality of substantially spiral sections each having a plurality of parallel ribs extending longitudinally along its inner face, each of the several4 sections being curved to form a single convolution of a spiral and being progressively smaller in size and arranged with the inner extremity of a larger spiral section abutting and overlapping the outer extremity of a next smaller spiral section, the ribs of 'each smaller section havinotheir free edges substantially in contact with the unribbed faces of a next larger section to form spiral silencing passageways, a casing enclosing said sections, means for rigidly securing said sections in assembled relation and :tor attaching each section alon one peripheral edge thereof to one end o said casing thereby leaving them free to expand or contract independently of each other or of the casing, and means for positioning and supporting the outermost section along its opposite peripheral edge without interfering with the capacity of the sections for independent expansion and contraction.

4. In a silencer, a winding passageway for the sound waves, formed by a plurality of sections extending longitudinally of the silencer, each section comprising one convolution of an approximate spiral curving outwardly from the longitudinal axis ofthe silencer and forming the sides of said passageway, the several sections being progressively smaller in size and arranged with the inner extremities of a larger part spiral section abuttin and overla ping the outer extremity of t e next sma ler part spiral section, sectlons` 1n' assembled relation;

5; In a silencer, a winding passageway for the. sound Waves, Jformed b a plurality of sections extending longitudinally of the silencer, each section comprising part of an approximate spiral curving. outwardly 'from v and .overlapping the outer extremity of the andvmeans for vrigidly ySecuripg'-saidr Vsignattnre.

nextpsmaller'part spiral section, a cylindrical casing enclosing said sections and having a header' member t'.herefor,v and means for 15' riidly securing said sections in assembled re ation including securing means for attaching said sections at one end only thereof to said header member thereb vleaving them free' to expand or contract ind the casing.

In testlmony whereof vI haveaixed my ependently of 2o' Hmm PERGY MAXIM. 

